GMO Investigator Lab

What are genetically modified organisms (GMOs)?

Organisms whose genetic material has been altered using genetic engineering techniques.

What is a common concern regarding GMOs?

The potential long-term effects of pesticides and herbicides on the environment and human health.

What is the stance of the biotechnology industry on GMOs?

They believe GMOs can solve food production issues and environmental concerns.

What are GMOs often referred to as by opponents?

Frankenfoods.

What is one method of genetic manipulation that has been used for centuries?

Crop breeding to encourage specific traits.

What is a popular class of GM crops that includes a gene from Bacillus thuringiensis?

Bt crops.

What protein do Bt crops produce that is lethal to pests?

Delta-endotoxin.

What is one benefit of planting Bt crops for farmers?

They do not need to apply pesticides.

What are some other traits that GM crops may possess?

Herbicide resistance, delayed fruit ripening, resistance to fungi or drought, and improved crop yield.

What is a major concern regarding the use of herbicide-resistant GM crops?

The potential creation of super-weeds through cross-pollination.

What is one argument made by proponents of GM foods?

They reduce the need for toxic chemicals in the environment.

What is the enzyme-linked immunosorbent assay (ELISA) used for?

To detect proteins produced specifically by GM crops.

Why is ELISA not useful for highly processed foods?

The proteins are likely destroyed during processing.

What method can be used to detect DNA sequences common to GM foods?

Polymerase chain reaction (PCR).

What is the first step in the laboratory protocol for testing GMOs?

Extract genomic DNA from food samples.

What is the purpose of the InstaGene matrix in DNA extraction?

To chelate metal ions that would degrade the DNA.

What should be done before processing the test sample in the lab?

Process the non-GMO control first to reduce contamination risk.

What is the purpose of centrifuging the samples after DNA extraction?

To remove the InstaGene matrix and debris, leaving intact extracted DNA.

What is the expected outcome of the PCR reaction using plant primers?

It should always amplify DNA from both GM and non-GM foods.

What does the PCR reaction using GMO primers indicate?

It will only amplify DNA if the test food is genetically modified.

What is the significance of the molecular weight ruler in electrophoresis?

It allows the sizes of the DNA bands to be determined.

What is the final step in the laboratory protocol for visualizing DNA?

Electrophoresing the amplified samples to visualize the DNA.

What is the purpose of grinding the food sample in the protocol?

To create a slurry for DNA extraction.

What method is used to detect DNA sequences common to GM foods?

Polymerase Chain Reaction (PCR).

Why is DNA more suitable for testing processed foods than proteins?

DNA is more resistant to processing and can be extracted from highly processed foods.

What is the first step in the laboratory procedure for detecting GMOs?

Extract genomic DNA from food samples.

What is the purpose of using plant primers in PCR?

To verify that viable DNA was successfully extracted from the food.

What happens if the test food is non-GM during PCR?

The GMO primers will not anneal, and no DNA will be amplified.

What is the role of a molecular weight ruler in electrophoresis?

To determine the sizes of the DNA bands.

What is the significance of centrifuging the samples after DNA extraction?

To remove the InstaGene matrix and debris, leaving intact extracted DNA.

What is PCR?

A method for amplifying specific sections of DNA in a test tube.

What components are required for PCR?

DNA template, DNA polymerase, two DNA primers, dNTPs, and buffers.

How does PCR help in gene cloning?

It provides large amounts of specific DNA sequences necessary for the process.

What is the purpose of amplifying DNA in PCR?

To make millions of copies of a target DNA sequence.

What should be done before processing the test sample?

Process the non-GMO control first.

What is the significance of using a positive control in PCR?

To ensure the PCR reaction works correctly.

What is the expected outcome if the PCR is successful?

Visible DNA bands on the gel after electrophoresis.

What does PCR stand for?

Polymerase Chain Reaction.

What is the purpose of primers in PCR?

Primers are short strands of DNA that are complementary to the DNA template and are necessary for amplification.

What is the role of DNA polymerase in PCR?

DNA polymerase copies the target DNA sequence by adding nucleotides to the 3' ends of the primers.

At what temperature does the denaturing step of PCR occur?

94°C.

At what temperature does the annealing step of PCR occur?

59 C

What is the optimal temperature for DNA polymerase activity during PCR?

72°C.

How many cycles are typically performed in a PCR reaction?

40 cycles.

What is the result of each complete cycle of PCR?

Each cycle doubles the number of target DNA molecules.

What is the significance of Taq DNA polymerase in PCR?

It is a thermostable enzyme that remains active at high temperatures used in PCR.

From which organism is Taq DNA polymerase isolated?

Thermus aquaticus, a thermophilic bacterium.

What is the purpose of using a non-GMO control in PCR experiments?

To ensure that the PCR reactions have not been contaminated with GMO-positive DNA.

What is gel electrophoresis used for in PCR?

To visualize PCR products and determine the presence or absence of target DNA sequences.

What is the main goal of the first PCR reaction using the plant master mix?

To confirm successful extraction of plant DNA by amplifying a common chloroplast gene.

What is the purpose of the second PCR reaction using the GMO master mix?

To determine if the DNA sample contains GM DNA sequences.

What is thermal cycling in PCR?

The rapid heating and cooling process that allows the PCR reaction to proceed through its steps.

Why must DNA polymerase be thermally stable for PCR?

Because the PCR reaction involves high temperatures that would denature most enzymes.

What is the purpose of using fresh pipet tips for each tube in PCR?

To prevent contamination of samples.

What can be concluded if DNA is amplified using plant primers but not GMO primers?

Plant DNA was successfully extracted, but the test food may not contain GM DNA.

What is the purpose of the control PCR reactions in the experiment?

To validate the results by confirming successful amplification of known DNA sequences.

What is the purpose of using a gel in electrophoresis?

To separate DNA fragments based on size.

What types of gels can be used for electrophoresis?

Agarose gel and polyacrylamide gel.

What is the recommended agarose gel concentration for separating PCR products?

3% agarose gel.

What is the purpose of loading dye in gel electrophoresis?

To visualize the sample and track its progress during electrophoresis.

What is the function of a molecular weight ruler in gel electrophoresis?

To provide a reference for determining the sizes of DNA bands.

What is the running buffer used for agarose gels?

1x TAE (Tris-Acetate-EDTA).

What is the running buffer used for polyacrylamide gels?

1x TBE (Tris-Borate-EDTA).

What is Fast Blast stain used for?

To stain DNA bands in the gel for visualization.

What should be done to prevent contamination when handling gels?

Wear gloves to handle the gels.

What is the purpose of using a tighter gel matrix?

To impede the movement of larger DNA bands for better separation.